In a refrigerant machine or heat pump, an accumulator is arranged downstream of an evaporator to catch different refrigerant volumes due to different operational conditions, and to keep a refrigerant reserve stock for balancing leakage losses during maintenance intervals. An internal heat exchanger functions to transfer heat within the system for supercooling from a warm high-pressure side to a cold low-pressure side (suction side), which in its turn is thereby heated, or overheated, respectively.
From DE 31 19 440 A1, hereby incorporated by reference herein in its entirety, a plant heat exchanger for refrigeration plants is known, the heat exchanger having an internal container arranged within an external container, whereby in the space between both containers there is a tube coil for the refrigerant flowing from the condenser to the evaporator. The exit line of the evaporator leads into the space, which through an overflow tube is connected to the internal container, from which suction into the compressor takes place. This embodiment regularly presents the problem that the can-like external container must expensively be equipped with the connections required for the various refrigerant lines.
For these connections, the inner tube ends have to be connected to the covers of the case, preferably from the interior. Current solutions known in the art are characterized by that the cylindrical ends of the tube coils are led through the external case and sealed to the exterior by welding, brazing, soldering or using screw connections, for example. Further connection of the components is always through a second screw connection at the same tube ends led through from the interior of the heat exchanger.
Such a solution is disadvantageous in that the connection points, which protrude far from the component, are highly susceptible to damage. Another disadvantage is that the tubes, when led through the cover or bottom of the container, are connected by metallurgical joining such as welding, brazing or soldering, which require much effort, are expensive, and are not very reliable. Additionally the heat input during metallurgical joining can adversely affect the mechanical properties of the materials. Accordingly, mechanical dimensioning must be based on thicker walls, or higher-grade materials must be used, processing of which is, in addition, more expensive. Further, cost-effective design cannot be realized when metallurgically joining from the exterior of the heat exchanger.
From DE 199 03 833 A1, hereby incorporated by reference herein in its entirety, an integrated collector-heat exchanger unit is shown which again consists of an intricately shaped container having refrigerant connections with accordingly sophisticated design. It is a particular disadvantage of the solutions to the state-of-the-art that the cases cannot be manufactured as efficiently as desired because the intricate geometries require steps of material processing and connection technologies which are complicated and expensive as well as susceptible to leakage.
Accordingly, it would be desirable to produce a combined internal heat exchanger and accumulator, wherein a cost of manufacture thereof and a space required thereby are minimized and an efficiency thereof is maximized.